A new study, published in the Early Edition of the journal PNAS, revealed that marine ecosystems can take thousands of years in order to recover from climate disturbances.
Researchers examined thousands of invertebrate fossils and now believe that that the ecosystem will recover from climate change and seawater deoxygenation only on a millennial scale. They looked closely at more than 5,400 invertebrate fossils found in a sediment region near the shores of Santa Barbara, California.
The sediment core is a slice of ancient ocean life as it was between 3,400 and 16,100 years ago. The data provides a picture of what happened during the last major de-glaciation. The new study reports on how long it has taken before for ecosystems to start their recovery following dramatic changes in climate.
California Academy of Sciences announced in a statement that this study is the first of its kind and has a revolutionary approach on the issue.
“In this study, we used the past to forecast the future. Tracing changes in marine biodiversity during historical episodes of warming and cooling tells us what might happen in years to come. We don’t want to hear that ecosystems need thousands of years to recover from disruption, but it’s critical that we understand the global need to combat modern climate impacts”, said author Peter Roopnarine from the California Academy of Sciences.
Previous marine sediment research were based on single-celled organisms named Foraminifera. Scientists explored multicellular life in this new study, focusing on invertebrates to get a more wide angle on the perspective of ocean ecosystem flexibility during past periods of climate change.
The sediment core exposed an ancient history of abundant, diverse, and well-oxygenated ecosystems on the seabed of seas and oceans. This period was followed by a time of oxygen loss and warming which seems to have caused a quick loss of biodiversity. The research found that invertebrate fossils are nearly extinct during times of low oxygen levels.
The study’s discoveries suggest that in the future, periods of severe global climate change may lead to similar devastating effects. This kind of developments could mean that ecosystems would need millennial periods to recover their full strenght As the Earth warms, researchers expect to see much larger parts of the world’s oceans that are low-oxygen “dead zones”.
Image Source: Ocean Tipping Points
